It's no surprise that Williams is at the royal wedding; she's a good friend of Meghan's. The two met at DIRECTV's Celebrity Beach Bowl in February 2014.

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Back in April, during a interview with Good Morning America, the tennis legend discussed whether or not she'll be attending the royal wedding and she was rather coy.

"I don’t know, I think it's during one of the tournaments, I'll see if I can make it," she said.

Williams was not coy about her feelings for Meghan though, gushing about her friend during the interview.

"I'm obviously super happy for her," Williams said. "She's such a great girl and she is incredibly nice and I couldn't be happier for her."

The feelings are mutual. Early in their friendship, Meghan wrote about her love for Williams on her now-defunct lifestyle website, The Tig.

"She quickly became a confidante I would text when I was traveling, the friend I would rally around for her tennis matches, and the down to earth chick I was able to grab lunch with just a couple weeks ago in Toronto," Meghan wrote.

Today, Serena will be able to witness her friend Meghan say "I do," to the love of her life.

Follow along here as we report on the royal wedding in real-time—from the dress to the tiara to Harry and Meghan's most adorable moments.

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